JP2008092717A - Charger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To charge an arbitrary battery cell while reducing effects of common-mode noise generated between the battery cell and a cyclic power supply. <P>SOLUTION: A charger is provided with a power storage device (20) in which a plurality of power storage device cells (E1, E2, ..., En) are connected in series and the pole of one of the power storage device cells is made as a reference potential point, a single or a plurality of capacitors (C1) whose one end potential is fixed to the potential of one pole of each power storage device cell and that of the other pole of each of the plurality of power storage device cells via rectification means (D11, D12), and a cyclic power supply (30) that is connected between the other arbitrary end of each of a plurality of the capacitors and the reference potential point of each power storage device so as to generate a repetitive signal while being connected to the reference potential point of the battery. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a battery charger for a battery in which a plurality of battery cells are connected in series.

  Electric vehicles such as electric vehicles, fuel cell vehicles, and hybrid vehicles have been put into practical use for environmental considerations, noise reduction, and gasoline consumption reduction. These electric vehicles include high-voltage batteries that drive a motor for traveling. It is installed. This high-voltage battery has a high voltage by connecting a plurality of normal low-voltage battery cells in series. By increasing the voltage of the battery, the current flowing to the traveling motor is reduced, and the low-voltage / same-output traveling battery is used. Compared with a motor, the weight of an electric wire can be reduced.

  By the way, when a plurality of battery cells connected in series are repeatedly charged and discharged, the charge amount of each battery cell gradually varies due to variation in characteristics of the battery cells. When one of the battery cells reaches the upper limit of charge, the charging operation must be stopped even if the other cell is not fully charged, and when one of the battery cells reaches the lower limit of charge, the discharge operation is performed. Must be stopped. That is, the charge capacity that can be used for reaching the upper limit of charge or the lower limit of charge in the entire series connection at an early stage is substantially reduced. In addition, there is a fine short circuit as one of the failure modes of the battery, and when this fine short circuit occurs, only the failed battery cell is discharged.

Therefore, in order to level the charge amount of the battery cell, a method is disclosed in which a series circuit of a resistor and a semiconductor switch is connected to both ends of each battery cell and discharged appropriately (Patent Documents 1, 2, and 5). 3). Further, a method is disclosed in which a transformer winding and a switching element are connected to each battery cell, and the charging voltage to each battery cell is leveled (Patent Documents 4 and 5). In the technique of discharging with a resistor, a high-breakdown-voltage semiconductor switch is required, and an accompanying circuit becomes complicated. Further, in the technology of insulating with a transformer, the transformer is relatively large among electronic components, and it is difficult to reduce the integration and size.
In addition, as a technology that relatively reduces such problems, charging the battery cells by isolating each battery cell and the AC power supply with a capacitor and superimposing the fluctuation voltage of the AC power supply on the voltage across the capacitor Has been disclosed (Patent Document 6).
JP 2000-92732 A JP 2001-37077 A JP 2003-70179 A JP 2002-223528 A JP 2001-339865 A JP-A-11-32443

  However, in the technique described in Patent Document 6, both poles of the battery cells connected in series and both poles of the AC power supply are insulated, and common mode noise is applied between the battery cell and the AC power supply (periodic power supply). In such a case, the battery cell may be charged including the noise voltage. Moreover, the technique of patent document 6 is supplying the same voltage simultaneously to several battery cells (electric storage cell) using one alternating current power supply.

  Therefore, an object of the present invention is to provide a charging device that can reduce the influence of common mode noise generated between a capacitor cell and a periodic power source and can charge any capacitor cell.

  In order to solve the above-described problem, the charging device according to the first aspect of the present invention, which is one means of the present invention, includes a plurality of capacitor cells connected in series, and a capacitor having a pole of any one of the capacitor cells as a reference potential point. And one or a plurality of capacitors in which the potential of one end is fixed to the potential of one of the electrodes of each of the storage cells and the other of the plurality of storage cells via a rectifier, A periodic power source connected between any other end of the plurality of capacitors and the reference potential point of the capacitor and connected to the reference potential point of the capacitor for generating a repetitive signal is provided.

  According to this, each pole of the battery cell and the periodic power supply are insulated via the capacitor, and the capacitor is charged with a voltage corresponding to the potential difference between the potential of each pole and the output voltage of the periodic power supply. For this reason, a voltage corresponding to the amplitude of the periodic power supply is charged in each capacitor cell via the capacitor and the rectifying means. Here, the periodic power source includes an AC power source and a rectangular wave power source, and the battery includes a battery and a capacitor. Note that the amplitude of the output voltage of the periodic power supply is preferably larger than the potential difference between any one pole of each capacitor cell and any other pole of the plurality of capacitor cells. In addition, since any of the capacitor cell poles and the periodic power supply are connected to the reference power supply, they are less susceptible to common mode noise.

  According to a second aspect of the present invention, in the charging apparatus according to the first aspect, the periodic power source is a rectangular wave power source that alternately outputs a high instantaneous voltage and a low instantaneous voltage, and the rectifying means. When the voltage of the rectangular wave power source is high, the potential of one end of the capacitor is fixed at a higher potential between the one pole and the other pole, and when the voltage of the rectangular wave power source is low, The potential at one end of the capacitor is fixed to the one having a lower potential between the other electrode and the other electrode.

  According to this, when the instantaneous voltage of the rectangular wave voltage is high, a plurality of capacitors connected between the higher pole and the reference potential via the higher pole at one pole and the other pole The cell is charged. In addition, when the instantaneous voltage of the rectangular wave power supply is low, one or a plurality of electrodes connected between the lower pole and the reference potential are connected via the lower pole between the one pole and the other pole. The capacitor cell is discharged. By this charging and discharging, only the battery cell connected between one pole and the other pole is charged.

  According to a third aspect of the present invention, there is provided the charging apparatus according to the second aspect, wherein the periodic power source includes a first periodic power source and a second phase whose phase is inverted with respect to the first periodic power source. The capacitor has a first capacitor in which the potential at the other end is fixed to the voltage of the first periodic power source, and the potential at the other end is fixed to the voltage of the second periodic power source. And a second capacitor.

  According to this, since the phases of the first rectangular wave power source and the second rectangular wave power source are inverted, one of the potentials is higher and the other potential is lower. For this reason, the capacitor connected to the rectangular wave power source having a high potential is fixed at the higher potential at each pole of the plurality of capacitor cells and the other pole. In addition, the capacitor connected to the rectangular wave power source having a low potential is fixed at the lower potential at each pole and the other pole of the plurality of capacitor cells. Therefore, a capacitor connected to a rectangular wave power source with a high potential, a capacitor cell connected between one pole and the other, and a capacitor connected to a rectangular wave power source with a low potential are used. A current flows between the rectangular wave power source and the low potential rectangular wave power source.

  The charging device according to claim 4, which is another means of the present invention, is a storage battery charging device that can charge any of the storage battery cells of a storage battery in which a plurality of storage battery cells are connected in series. The anode side of the first diode and the cathode side of the second diode are connected to one end, the cathode side of the first diode is the anode of each capacitor cell, and the anode side of the second diode is the respective anode A charging circuit having a plurality of sub-circuits connected to the cathode of each storage cell for each storage cell; and a rectangular-wave power source for applying a rectangular wave to the other end of the capacitor of any sub-circuit included in the charging circuit. It is characterized by that.

  When the instantaneous voltage of the rectangular wave power supply is high, the plurality of capacitor cells are charged via the capacitor and the first diode. On the other hand, when the output voltage of the rectangular wave power source is low, the capacitor cell and the second diode are discharged from the capacitor cell or cells connected to the reference potential. By this charging and discharging, only the battery cell connected between the first diode and the second diode is charged.

  Moreover, the charging device according to claim 5, which is another means of the present invention, is a charging device for a capacitor capable of charging any of the capacitor cells of a capacitor (20) in which a plurality of capacitor cells are connected in series. The anode side of the first diode and the cathode side of the second diode are connected to one end of the first capacitor, and the cathode side of the first diode is connected to the anode of each capacitor cell. The anode side of the diode is connected to the cathode of each capacitor cell, the anode side of the third diode and the cathode side of the fourth diode are connected to one end of the second capacitor, and the cathode of the third diode A plurality of sub-circuits, each having a side connected to the anode of each capacitor cell and the anode side of the fourth diode connected to the cathode of each capacitor cell, for each capacitor cell A rectangular wave voltage is applied to the other end of the first capacitor of an arbitrary sub-circuit included in the charging circuit, and an inverted voltage obtained by inverting the rectangular wave voltage is applied to the other end of the second capacitor. And a rectangular wave power source to be applied.

  According to this, since the phases of the first rectangular wave power source and the second rectangular wave power source are inverted, one of the potentials is higher and the other potential is lower. When the potential of the first rectangular wave power source is high, a current flows to the second rectangular wave power source via the first capacitor, the first diode, the capacitor cell, the fourth diode, and the second capacitor. Charge the storage cell. On the other hand, when the potential of the second rectangular wave power source is high, a current flows to the first rectangular wave power source through the second capacitor, the third diode, the capacitor cell, the second diode, and the first capacitor. This capacitor cell is charged. That is, the capacitor cell is charged regardless of which of the first rectangular wave power source and the second rectangular wave power source has a high potential.

  According to a sixth aspect of the present invention, in the charging device according to the fifth aspect, the central voltage of the rectangular wave voltage and the central voltage of the inverted voltage have a constant potential difference. This also charges the battery cell based on the change in amplitude of the rectangular wave voltage and the change in amplitude of the inversion voltage.

  The invention according to claim 7 is the charging device according to claim 4 or 6, wherein a pole of any one of the capacitor cells and a reference potential of the rectangular wave power source are the same potential. . According to this, the influence of the common mode noise generated between the battery cell and the rectangular wave power source is reduced.

  According to an eighth aspect of the present invention, in the charging device according to any one of the fourth to seventh aspects, the capacitor, the rectangular wave power source, and at least one of a resistance and an inductance are provided on the energization path. . According to this, the transient current can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the influence of the common mode noise which generate | occur | produces between an electrical storage cell and a periodic power supply can be decreased, and arbitrary electrical storage cells can be charged.

(First embodiment)
A charging apparatus according to an embodiment of the present invention will be described with reference to the drawings.
In the configuration diagram of FIG. 1, the charging device 100 includes a battery (battery) 20 in which n battery cells (capacitor cells) E1, E2,..., En are connected in series, and each battery cell E1, E2,. , A pulse application circuit 30 that is a periodic power source (rectangular wave power source) that generates a rectangular wave that drives the charging circuit 10, and a cell that measures the voltage of each of the battery cells E1, E2,. And a voltage detection circuit 25. The battery 20 is connected to a load. The pulse application circuit is connected to a vehicle control device grounded to the vehicle body via an insulation circuit. The reference potentials of the battery 20, the charging circuit 10, and the pulse applying circuit 30 are insulated from the vehicle body without being grounded.

The battery 20 is typically a lithium ion battery, the potentials at both ends are maintained at V0 and Vn, and the potentials at the connection points of the battery cells E1, E2,..., En are V1, V2,. 1 is maintained. In other words, the potentials at the connection points of the load and the battery cells E1, E2,..., En are V0, V1, V2,. The cell voltage detection circuit 25 is composed of n detection circuits so as to detect a potential difference between the battery cells E1, E2,. Each detection circuit includes an operational amplifier circuit OA1, OA2, ..., and OAn, the operational amplifier OA1, OA2, ..., capacitor _{C 01,} C 02 connected in parallel to the input of OAn, _..., and _{C 0n,} the capacitors _{C 01} , C ₀₂ ,..., C _0n and resistors r11, r12, r21, r22,... Rn1, rn2 connected between the battery cells E1, E2,. ing. These capacitor C ₀₁ , C ₀₂ ,..., C _0n and resistors r11, r12, r21, r22,..., Rn1, rn2 prevent normal mode noise. Each detection circuit is required for leveling the charge amounts of the battery cells E1, E2,..., En, and is not necessary for a charging device that does not need to perform leveling. The operational amplifier circuits OA1, OA2,..., OAn preferably use isolation amplifiers.

  Next, the configuration of the charging circuit 10 that is a characteristic configuration of the present embodiment will be described. Since the same circuit is formed for each of the battery cells E1, E2,..., En, the circuit of the battery cell E1 will be described. . The cathode of the diode D11 is connected to the anode of the battery cell E1 via a resistor R11 for current limitation, and the anode of the diode D12 is connected to the cathode of the battery cell E1 via a resistor R12. The anode of the diode D11 and the cathode of the diode D12 are connected to one end of the capacitor C1, and the output signal of the pulse applying circuit 30 is input to the other end of the capacitor C1. The cathode of the battery cell En is used as the reference potential of the charging device.

  The pulse application circuit 30 is provided with a plurality of circuits for applying a pulse voltage to the other ends of the capacitors C1, C2,. Here, for convenience of explanation, a circuit connected to the other end of the capacitor C1 will be described. In the pulse application circuit 30, the series circuit of the Hi-side switch S1 and the Lo-side switch S2 is maintained at the power supply potential Vp between the reference potential and the connection point between the switch S1 and the switch S2 is the capacitor C1. Connected to the other end. The switch S1 is controlled by a pulse voltage by the control circuit, and the switch S2 is controlled by an inverted signal obtained by inverting this pulse voltage by the inverter INV. As a result, when the switch S1 changes from the OFF state to the ON state and the switch S2 changes from the ON state to the OFF state, the other end of the capacitor C1 changes from the reference potential to the power supply potential Vp. On the other hand, when the switch S1 transitions from the ON state to the OFF state and the switch S2 transitions from the OFF state to ON, the other end of the capacitor C1 transitions from the power supply potential Vp to the reference potential.

Next, the operation of the charging apparatus 100 will be described with reference to FIG.
FIG. 2A is a diagram for explaining the operation when the cell is charged from the capacitor by transitioning from the reference potential to the power supply potential Vp, and FIG. 2B is the diagram illustrating the transition from the power supply potential Vp to the reference potential. It is a figure for demonstrating operation | movement when recharging.
In FIG. 2A, when the other end of the capacitor C1 transitions from the reference potential to the power supply potential Vp (FIG. 1), the potential of the capacitor C1 rises as a whole by the power supply potential Vp, so that the capacitor C1, the diode D11, and A current i ₊ flows to the battery cells E1, E2, ..., En via the resistor R11. On the other hand, the cathode potential V1 of the battery cell E1 is generally lower than the potential of the capacitor C1 which is increased by the power supply potential Vp, so that the diode D12 is turned off. Thereby, the electric charge of C1 is discharged, and the electric potential of the capacitor terminal on the side connected to the diode converges to the electric potential of V0. Note that the power supply potential Vp, which is an instantaneous voltage of a rectangular wave voltage, is higher than the reference potential.

Further, in FIG. 2B, when the other end of the capacitor C1 transitions from the power supply potential Vp to the reference potential, the potential of the capacitor C1 is lowered by the power supply potential Vp as a whole, so that the resistor R12, the diode D12, and the capacitor The current i ₋ is discharged from the battery cells E2,..., En via C1. On the other hand, the anode potential V0 of the battery cell E1 becomes higher than the potential of the capacitor C1 that is lowered by the power supply potential Vp as a whole, so that the diode D11 is turned off. As a result, the potential of the capacitor terminal on the side where the charge is charged in C1 and connected to the diode converges to the potential of V1.

  In the state of FIG. 2A, the battery cells E1, E2,..., En are charged, while in the state of FIG. 2B, the battery cells E2,. Only the battery cell E1 is charged.

FIG. 3 shows a circuit operation result in the case where n = 3 and only the middle-stage battery cell E2 is charged.
The pulse application circuit 30 (FIG. 1) is composed of a connection circuit of p-channel MOSFETs M11, M21, and M31 and n-channel MOSFETs M12, M22, and M32 in FIG. 3, and includes a p-channel MOSFET M21 and an n-channel MOSFET M22. A pulse signal Vs is input to the gate. Note that the gates of the MOSFETs M11, M12, M31, and M32 are maintained at the reference potential.

  4A shows the current waveform flowing through the battery cell E1, FIG. 4B shows the current waveform flowing through the battery cell E2, and FIG. 4C shows the current waveform flowing through the battery cell E3. In the circuit of FIG. 3, as shown in FIG. 4A, the battery cell E1 is not charged / discharged, and as shown in FIG. 4B, the battery cell E2 only has a charging current via the diode D21. Flows and no discharge current flows. Further, as shown in FIG. 4C, the battery cell E3 is alternately supplied with the charging current via the diode D21 and the discharging current via the diode D22, and the steady state in which the charging current and the discharging current are balanced. Then, the average current becomes zero.

  As described above, according to the present embodiment, the connection points of the battery cells E1, E2,..., En and the load and the pulse application circuit 30 are insulated via the capacitors C1, C2,. In addition, a voltage corresponding to the potential difference between each electrode and the pulse application circuit 30 is charged. A plurality of battery cells connected between the anode and the reference potential via the anode of the battery cell E1 when the voltage of the rectangular wave voltage generated by the pulse applying circuit 30 is maintained at the power supply voltage Vp. E1, E2, E3,..., En are charged. In addition, when the voltage of the rectangular wave power supply is a voltage with respect to the reference potential, the battery cell or cells connected between the connection point and the reference potential via the connection point between the battery cell E1 and the battery cell E2 Charges are discharged from E2, E3,. By this charging and discharging, only the battery cell E1 is charged. Further, since the battery 20 and the pulse applying circuit 30 are connected at a common potential, common mode noise is unlikely to be charged in the capacitors C1, C2,.

(Second Embodiment)
In the first embodiment, in order to charge one battery cell E1, the other battery cells E2, E3,..., En are charged / discharged, but only the battery cell E1 can be charged. The charging apparatus of this embodiment is demonstrated using the block diagram of FIG.
The charging device 150 includes a cell voltage detection circuit 25, a battery 20, a charging circuit 15, and a pulse application circuit 35. Since the cell voltage detection circuit 25 and the battery 20 have the same configuration as that of the first embodiment, the description thereof will be omitted, and the charging circuit 15 and the pulse application circuit 35 will be described. As in the first embodiment, the pulse application circuit 35 is connected with the cathode of the battery cell En as a reference potential.

  The charging circuit 15 performs charging for each of the battery cells E1, E2,..., En, and includes a plurality of identical circuits. For example, the circuit for charging the battery cell E1 includes diodes D11, D12, D13, and D14, capacitors C11 and C12, and resistors R11 and R12. The anode of the battery cell E1 constituting the battery 20 is connected to the cathode of the diode D11 and the cathode of the diode D13, and the cathode of the battery cell E1 is connected to the anode of the diode D12 and the anode of the diode D14. A pulse signal is input to the anode of the diode D11 and the anode of the diode D12 via the capacitor C11 and the resistor R11. Further, an inverted signal obtained by inverting the pulse signal is input to the cathode of the diode D13 and the cathode of the diode D14 via the capacitor C14 and the resistor R12. The diodes D11, D12, D13, and D14 constitute a full wave rectifier circuit.

  The pulse application circuit 35 generates a pulse signal to be applied to the resistor R11 of the charging circuit 15 and an inverted signal of this pulse signal. A series circuit of the Hi-side switch S11 and the Lo-side switch S12 is maintained at the power supply potential Vp between the reference potential and the connection point between the switch S21 and the switch S22 is connected to the resistor R12. In addition, the series circuit of the Hi-side switch S21 and the Lo-side switch S22 is maintained at the power supply potential Vp between the reference potential and the connection point between the switch S21 and the switch S22 is connected to the resistor R12. Yes.

  The switch S11 is controlled by a pulse signal from the control circuit, and the switch S12 is controlled by an inverted signal obtained by inverting this pulse voltage by the inverter INV1. The switch S21 is controlled by a signal obtained by inverting the pulse signal from the control circuit by the inverter INV3, and the switch S22 is controlled by a signal obtained by inverting the signal inverted by the inverter INV3 by the inverter INV2. As a result, the potential at the connection point between the switch S11 and the switch S12 is inverted with respect to the potential at the connection point between the switch S21 and the switch S22.

Next, the operation of the charging device 150 will be described with reference to FIG.
FIG. 6A shows a case where a positive pulse signal is applied to the resistor R11 and an inverted signal is applied to the resistor R12. FIG. 6B shows a case where a positive pulse signal is applied to the resistor R12, The case where an inversion signal is applied to the device R11 is shown.
In FIG. 6A, current flows through the path of the resistor R11, the capacitor C11, the diode D11, the battery cell E1, the diode D14, the capacitor C12, and the resistor R12, and the battery cell E1 is charged. In this state, the diodes D12 and D13 are turned off. In FIG. 6B, a current flows through the path of the resistor R12, the capacitor C12, the diode D13, the battery cell E1, the diode D12, the capacitor C11, and the resistor R11, and the battery cell E1 is charged. In this state, the diodes D11 and D14 are turned off.

Next, the circuit operation result of this embodiment will be described.
FIG. 7 is a circuit diagram in the case where n = 2 and only the battery cell E1 is charged, and FIG. 8 is a voltage and current waveform of each part.
At this time, the current flowing through the diode D11 is a current _{I A,} the current flowing through the diode D13 is a current _{I B,} the current flowing through the battery cell E1 is a current _{I c.}

8 (a) is a waveform of the pulse signal _{V A,} FIG. 8 (b) is a waveform of the inverted signal _{V B,} Fig. 8 (c) is a waveform of the current _{I A,} FIG. 8 (d) is a waveform of the current _{I B,} FIG. 8 (e) is a waveform of the current _{I C.} The horizontal axis of these waveforms indicates time T. Pulse signal V _A is the current I _A flows when the high phase, the inverted signal V _B is the current I _B flows when the high phase. The current I _C flowing through the battery cell E1, the current the current flowing through the diode D11 flows in I _A and diode D13 is a superposition of the I _B, flowing continuous charging current.

  As described above, according to the present embodiment, the phase of the rectangular wave power source constituted by the switches S11 and S12 and the rectangular wave power source constituted by the switches S21 and S22 are reversed, so that any rectangular shape is obtained. The potential of the wave power source is higher and the other potential is lower. For example, when the rectangular wave power source composed of S11 and S12 has a higher potential, the capacitor C11 converges and is fixed to the potential of the anode of the battery cell E1, which is the connection point with the higher potential. The capacitor C12 converges and is fixed at the cathode potential of the battery cell E1. Therefore, a current flows between the rectangular wave power source and the rectangular wave power source via the capacitor C11, the battery cell E1, and the capacitor C12. Also in this case, as in the first embodiment, since the cathode of the battery 20 is used as the reference potential of the pulse applying circuit 35, common mode noise is unlikely to be charged in the capacitors C11 and C12.

(Comparative example)
A comparative example will be described with reference to FIG. In each of the above embodiments, the rectangular wave voltage is applied using the pulse applying circuits 30 and 35. However, in this comparative example, driving is performed using an AC power supply.
In the circuit diagram of FIG. 9A (see Patent Document 6), in the charging device of this comparative example, four battery cells E1, E2, E3, E4 are connected in series, and each battery cell E1, E2, E3, E4 is connected. Are connected to the cathodes of the diodes D11, D21, D31, and D41 and one ends of the capacitors C11, C21, C31, and C41, and to the cathodes of the battery cells E1, E2, E3, and E4, are the diodes D12, D22, D32, and D42. Are connected, the cathodes of the diodes D12, D22, D32, D42, the anodes of the diodes D11, D21, D31, D41, and one end of the capacitors C12, C22, C32, C42 are connected, and the capacitors C11, C21, C31 are connected. , C41 is connected to one end of the AC power supply AC1 through resistors R11, R21, R31, R41. It has been continued. The other ends of the capacitors C12, C22, C32, and C42 are connected to the other end of the AC power supply via resistors R12, R22, R32, and R42. The AC power supply AC1 and the battery cells E1, E2, E3, and E4 are not connected at a common potential, and are only insulated by capacitors C11, C21, C31, C41, C12, C22, C32, and C42. Therefore, it is affected by the common mode noise vn.

  As shown in FIGS. 9B and 9C, it is conceivable to connect the cathode of the battery cell E4 and one of the AC power supplies AC1 to avoid the influence of the common mode noise vn (FIG. 9A). . However, when the resistor R12 and the cathode of the battery cell E4 are connected as a common potential as shown in FIG. 9B, an alternating current flows through the resistor R11, the capacitor C11, and the battery cells E1, E2, E3, and E4. Only and no charging is done. When the resistor R11 and the cathode of the battery cell E4 are connected as a common potential as shown in FIG. 9C, the connection point between the diodes D11, D21, D31, D41 and the diodes D12, D22, D32, D34 is used. In this circuit, an alternating voltage is applied, but an alternating current flows through the capacitors C12, C22, C32, and C42, and no current in any direction flows through the capacitors C11, C21, C31, and C41. For this reason, the circuit of FIG. 9C has a circuit configuration substantially similar to that of the first embodiment (FIG. 1).

  Next, referring to FIG. 10, the circuit of FIG. 9A will be examined from another viewpoint. FIGS. 10A and 10B are provided with two AC power supplies AC1 and AC2 connected to a reference potential, and in the same manner as FIGS. 9B and 9C, a battery for avoiding the influence of common mode noise vn. The cathode of the cell E4 is set as a reference potential. Only circuits related to the battery cell E1 are shown, and circuits related to the other battery cells E2, E3, and E4 are omitted.

  In FIG. 10A, with respect to the AC power supply AC1, only an AC current flows through the battery cells E1, E2, E3, and E4 via the resistor R11 and the capacitor C11, and the battery cell E1 is not charged. . For AC power supply AC2, a positive current flows through battery cells E1, E2, E3, and E4 via resistor R12, capacitor C12, and diode D11 when the voltage is positive. When the voltage is negative, a negative current flows through the diode D12, the capacitor C12, and the resistor R12 to discharge the battery cells E2, E3, and E4. Therefore, only the battery cell E1 is charged, and the battery cells E2, E3, E4 are not charged.

  In FIG. 10B, the diode D13 is inserted between the capacitor C11 and the diode D11 and the anode of the battery cell E1. When the phase difference between the AC power source AC1 and the AC power source AC2 is 180 degrees, the AC power source AC1 is a positive potential, and the AC power source AC2 is a negative potential, the resistor R11, the capacitor C11, and the diode D13. A current flows through the path of the battery cell E1, the diode D12, the capacitor C12, and the resistor R12. On the other hand, when the AC power supply AC1 has a negative potential and the AC power supply AC2 has a positive potential, a current flows through the path of the resistor R12, the capacitor C12, the diode D11, the capacitor C11, and the resistor R11. Therefore, only the battery cell E1 is charged, and the battery cells E2, E3, E4 are not charged.

  The charging device in FIG. 10C is obtained by replacing the diode D13 in FIG. 10B with a resistor R1 and replacing D12 with R3. When the AC power supply AC1 is at a positive potential and the AC power supply AC2 is at a negative potential, the battery passes through the path of the resistor R11, the capacitor C1, the resistor R1, the battery cell E1, the resistor R3, the capacitor C2, and the resistor R12. A charging current flows through the cell E1. On the other hand, when the AC power supply AC1 has a negative potential and the AC power supply AC2 has a positive potential, there are two current paths. The first path is the path of the resistor R12, the capacitor C2, the diode D11, the capacitor C1, and the resistor R11, and the second path is the resistor R12, the capacitor C2, the resistor R3, the battery cell E1, and the resistor. This is the path of R1, capacitor C1, and resistor R11.

  In this case, there is an advantage that the number of diodes is small, while the second path discharges the electric charge charged in the battery cell E1. The AC power supply AC1 and the AC power supply AC2 have the same amplitude, the capacitors C1 and C2 have the same capacitance, the resistors R1 and R3 have the same resistance value, and the resistors R11 and R12 have the same resistance. If the values are equal, the battery cells E2, E3, E4 are not charged.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications such as the following are possible.
(1) In the second embodiment, the cathode of the battery cell En is used as the reference potential of the switches S12 and S22 of the pulse application circuit 35. However, the other battery cells E1, E2,. You can also. Specifically, FIG. 11A shows the maximum potential of the anode of the battery cell E0 as the reference potential, and FIG. 11B shows the cathode of the battery cell E2 that is the intermediate potential, that is, the battery cell E3. The anode is used as a reference potential.
(2) In the second embodiment, since the diodes D11, D12, D13, and D14 are directly connected to the battery cells E1, E2,..., En, the battery cell E1 flows as shown in FIG. current I _C includes a pulse-like noise component. As shown in FIG. 12, one end of resistors r1 and r2 is connected to both ends of the battery cell E1, and a capacitor C0 is connected to the other ends of the resistors r1 and r2, so that noise components can be removed.
(3) In each of the above embodiments, the charging circuit 10 is driven using the rectangular wave generated by the pulse applying circuits 30 and 35. However, the charging circuit 10 can be driven using a sine wave.
(4) In each of the above embodiments, a resistor for limiting the amount of current is inserted in the middle of the energization path, but the same effect can be obtained by inserting an inductor instead of the resistor. In addition, by connecting the resistor and the inductor in series, the amount of current can be limited even by a resistor having a lower resistance, so that the power consumed by the resistor can be reduced. Resistors or inductors for limiting the amount of current can be arranged at any location on the energization path, and can be divided into a plurality. Further, when the resonance frequency of the circuit including the inductor and the capacitor is approximated to the frequency of the rectangular wave voltage, the rectangular wave generated by the pulse applying circuits 30 and 35 is generated by the voltages charged in the battery cells E1, E2,. May be higher than voltage. In this case, the rectangular wave voltages generated by the pulse applying circuits 30 and 35 may be lower than the voltages of the battery cells E1, E2,.
(5) In each of the above embodiments, the battery 20 is used as a capacitor, but it can also be applied to a capacitor.

It is a block diagram of the charging device which is one Embodiment of this invention. It is a figure for demonstrating operation | movement of the charging device which is one Embodiment of this invention. It is a circuit diagram of the charging device which is one Embodiment of this invention. It is a figure which shows the circuit operation result of the charging device which is one Embodiment of this invention. It is a block diagram of the charging device which is other embodiment of this invention. It is a figure for demonstrating operation | movement of the charging device which is other embodiment of this invention. It is a circuit diagram of the charging device which is other embodiment of this invention. It is a figure which shows the circuit operation result of the charging device which is other embodiment of this invention. It is a figure which shows the comparative example of the charging device of this invention. It is a figure for considering the comparative example of the charging device of this invention. It is a figure which shows the modification of the charging device of this invention. It is a figure which shows the other modification of the charging device of this invention.

Explanation of symbols

10, 15 Charging circuit 20 Battery (capacitor)
25 Cell voltage detection circuit 30, 35 Pulse application circuit 100, 150 Charging device

E1, E2, E3, E4, En Battery cell (capacitor cell)
D11, D12, D13, D14, D21, D22 Diode C0, C1, C2, C11, C12 Capacitor S1, S2, S11, S12, S21, S22 Switch AC1, AC2 AC power supply

Claims (8)

A plurality of capacitor cells are connected in series, and a capacitor having a reference potential point as a pole of any one of the capacitor cells;
One or a plurality of capacitors in which the potential at one end is fixed via a rectifier to the potential of one of the electrodes of each of the capacitor cells and the other electrode of any of the plurality of capacitor cells;
A charging apparatus comprising: a periodic power source connected between an arbitrary other end of the plurality of capacitors and a reference potential point of the battery and generating a repetitive signal. The periodic power source is a rectangular wave power source that alternately outputs a high instantaneous voltage and a low instantaneous voltage,
The rectifying means fixes the potential of one end of the capacitor to a higher potential at the one pole and the other pole when the instantaneous voltage of the rectangular wave power source is high, and the instantaneous voltage of the rectangular wave power source is 2. The charging device according to claim 1, wherein when the voltage is low, the potential at one end of the capacitor is fixed to a lower potential between the one electrode and the other electrode. The periodic power source includes a first periodic power source and a second periodic power source whose phase is inverted with respect to the first periodic power source,
The capacitor has a first capacitor whose other end is fixed at the voltage of the first periodic power supply, and a second capacitor whose other end is fixed at the voltage of the second periodic power supply. The charging device according to claim 2, comprising: A battery charger that can charge any of the battery cells of the battery connected in series with a plurality of battery cells,
The anode side of the first diode and the cathode side of the second diode are connected to one end of one capacitor, and the cathode side of the first diode is connected to the anode of each capacitor cell. A charging circuit comprising a plurality of sub-circuits, each having an anode side connected to the cathode of each capacitor cell, for each capacitor cell;
A charging device comprising: a rectangular wave power source that applies a rectangular wave to the other end of a capacitor of an arbitrary sub-circuit included in the charging circuit. A battery charger that can charge any of the battery cells of the battery connected in series with a plurality of battery cells,
The anode side of the first diode and the cathode side of the second diode are connected to one end of the first capacitor, and the cathode side of the first diode is connected to the anode of each capacitor cell, and the second diode The anode side of the third diode is connected to the cathode of each capacitor cell, the anode side of the third diode and the cathode side of the fourth diode are connected to one end of the second capacitor, and the cathode side of the third diode is connected A charging circuit comprising a plurality of sub-circuits for each capacitor cell, the anode side of each capacitor cell being connected to the anode side of the fourth diode to the cathode of each capacitor cell;
A rectangular wave power source that applies a rectangular wave voltage to the other end of the first capacitor of an arbitrary sub-circuit included in the charging circuit, and applies an inverted voltage obtained by inverting the rectangular wave voltage to the other end of the second capacitor; A charging device comprising:   The charging device according to claim 5, wherein a center voltage of the rectangular wave voltage and a center voltage of the inverted voltage have a constant potential difference.   7. The charging device according to claim 4, wherein a pole of any one of the battery cells and a reference potential of the rectangular wave power source are the same potential.   8. The charging device according to claim 4, further comprising at least one of a resistor and an inductor on an energization path between the capacitor and the rectangular wave power source.

Images